The Stanley Parable

Superficially a first-person walking simulator, The Stanley Parable has
the player wandering around their abandoned office building - where is
everyone? While exploring, a voiceover addresses what the player’s
avatar is doing or thinking, often in a humorous manner. This narrative
is key, as it examines what it means to play games and what exactly it
means to be a player in such a designed environment. It is intended to
be played many times and has multiple endings, but a couple of hours
play will uncover most of them. Well-made, thought-provoking and funny;
The Stanley Parable is closer to an interactive art experience than a
game (in my opinion).

The Stanley Parable is out on the Steam
store for PC, Mac and Linux
at US$14.99. It has been bundled many times.